I bought this lens recently and it came with a lens filter that could not be easily removed
due to being screwed on crookedly. I was able to get the filter off, but perhaps I used too much force
and when I turned the focusing ring the front off the lens unscrewed all of the way off.
I put it back together, but now the the focusing ring is loose. It focuses the lens, but it does not move the
distance indicator and it also moves away from it sometimes.

Any possible solutions?
Thanks.
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Last edited by uddhava on Sat Jul 07, 2018 9:09 pm; edited 1 time in total

It is likely that with so much force applied a setscrew was lifted up and moved off its detent.
You may want to take the rubber cover off the focus grip to see if you can find the setscrew head.
Otherwise this thing is going to need serious disassembly to find everything that's wrong.
There is some kind of interlock with the focus scale also._________________I like Pentax DSLR's, Exaktas, M42 bodies of all kinds, strange and cheap Japanese lenses, and am dabbling in medium format/Speed Graphic work.

It is likely that with so much force applied a setscrew was lifted up and moved off its detent.
You may want to take the rubber cover off the focus grip to see if you can find the setscrew head.
Otherwise this thing is going to need serious disassembly to find everything that's wrong.
There is some kind of interlock with the focus scale also.

Thank you. I will show more photos and have more questions shortly.
I hope some one with this lens will have some ideas.

I have opened up several Tamron lenses and they all have one thing in common -- a two-piece focusing collar. The pieces are held together with tape. It's some tough tape, but I reckon it can be sheared if enough force is brought against it. The handy thing about using tape is it is very easy to set infinity focus with this sort of setup. I have used just regular old 3M Scotch Magic tape and 3M's blue painter's tape. The magic tape I used on a repair maybe 6 or 7 years ago. The blue tape I used on a repair maybe 10 or 12 yeas ago. They're both still hanging in there, just fine.

If you peel back your focusing collar's rubber section, this should expose the tape. Inspect it for damage. If it's still intact, then your problem lies elsewhere._________________Michael

I have opened up several Tamron lenses and they all have one thing in common -- a two-piece focusing collar. The pieces are held together with tape. It's some tough tape, but I reckon it can be sheared if enough force is brought against it. The handy thing about using tape is it is very easy to set infinity focus with this sort of setup. I have used just regular old 3M Scotch Magic tape and 3M's blue painter's tape. The magic tape I used on a repair maybe 6 or 7 years ago. The blue tape I used on a repair maybe 10 or 12 yeas ago. They're both still hanging in there, just fine.

If you peel back your focusing collar's rubber section, this should expose the tape. Inspect it for damage. If it's still intact, then your problem lies elsewhere.

OK, thank you. I was wondering if that is what held them together because I couldn't find anything else.
The tape is there, but when I reassembled the lens it became crunched up so that it was no longer sticking to the
focusing scale. So I can remove the old tape and replace it with the type you recommended?

Thank you for the offer Craig, fortunately I was able to fix it by replacing the tape as Michael suggested.
Now I noticed that the aperture ring is cracked, I guess I will fix that with some clear tape.
I like this lens. My only complaint with it is the aperture ring is hard to use because of it's position, small size and lack of a
good grip.
Here are some photos.
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Wow, looking mighty nice! I'm glad to read that my suggested repair worked out for you. Maybe a small drop of super glue might "weld" your aperture ring back together? It works great on some plastics and not at all on others.

Which tape did you use? I suspect that any number of tapes with good adhesive properties and shear strength will work in this application. I honestly didn't give much thought to either of the tapes I chose. They were simply what were convenient -- close to hand, in other words -- at the time I used them, but fortunately they worked out well._________________Michael

Wow, looking mighty nice! I'm glad to read that my suggested repair worked out for you. Maybe a small drop of super glue might "weld" your aperture ring back together? It works great on some plastics and not at all on others.

Which tape did you use? I suspect that any number of tapes with good adhesive properties and shear strength will work in this application. I honestly didn't give much thought to either of the tapes I chose. They were simply what were convenient -- close to hand, in other words -- at the time I used them, but fortunately they worked out well.

Thanks again for the help. I'm glad it wasn't to difficult of a fix. I used some PVC insulating tape
that I found at the local hardware store. I hope it holds up.
It's funny you mention the super glue because that what I used and it is working so far. I think I
will like this lens although I have read that 35-70mm 17A and the 35-80mm 01A are both better.
I like being able to shoot at 28mm.

I think I
will like this lens although I have read that 35-70mm 17A and the 35-80mm 01A are both better.
I like being able to shoot at 28mm.

So have I and so do I. I bought my 28-80 with the hopes that it would rival the famed Vivitar S1 28-90. I actually bought a copy of the 35-80 because of the rave reviews (with sample photos added for effect) it received here. But you know what? I think your photos clearly show just how good this lens is. You've got some very remarkable shots here. I'm less inclined to think I'll have to take my 35-80 on
outings when I can put this one in my bag.

I own a Vivitar S1 28-90, and I've always liked the 28-90, but mine is in Nikon mount. And when I'm shooting with a film camera, such as one of my Canons or Pentaxes or Minoltas, or even my Contax or Fujica -- I have the Tamron and its adaptall-2 mount, which makes it so useful. Seeing just how nice and sharp your lens can be has convinced me that it is approximately equivalent to the S1 28-90. A big "plus" in its favor._________________Michael